Re: Is "malfunctioning" absolute or relative?

On Oct 14, 8:42 am, papa_r...@xxxxxxxxxxx wrote:
On 14 oct, 08:48, Uncle Ben <b...@xxxxxxxxxxx> wrote:





On Oct 14, 7:12 am, papa_r...@xxxxxxxxxxx wrote:

On 14 oct, 02:23, Uncle Ben <b...@xxxxxxxxxxx> wrote:

On Oct 14, 12:46 am, shuba <tim.sh...@xxxxxxxxxxxxx> wrote:

Uncle Ben wrote:
I guess we have to leave it that in your view the "bending of the
stick" immersed in a glass of water is real.  And in my view, the
bending of the stick is a misinterpretation of what we see in the real
bending of light rays from the scene.

I wouldn't actually use the term 'real' to describe the bent
stick, but neither would I use it for the length contraction and
time dilation of relativity, except perhaps to say they are real
geometric projections.

If we cannot agree on this little demonstration, then we are doomed to
disagree.
That's OK.

(But it still bothers me a little that if the bending of the stick is
real, why doesn't it break?)

Same reason that the same stick can be (really) Lorentz
contracted to any arbitrarily small length without breaking.

         ---Tim Shuba---

I don't think so. A lorentz contraction merely shortens the stick.  If
its ends are not constrained, there is no stress involved.  Whereas
the stick in water is bent sharply at one point.  If it is a rubber
stick, OK, but if it is a dead stick and were really bent, it would
certainly break.

I am perhaps only illustrating what I mean by "real", as you are using
your definition. I gather that we have a "real" disagreement about the
relativistic effects.  Let's agree on that, anyway.  I don't want to
get hung up on cute ideas about what is meant by being real.

Notice that I am not appealing to any one frame as giving real lengths
or times.  They are all real; they are just frame-relative.  This is
just as simple as the compass needles' "north" in London and New York
pointing in directions defined relative to their locations. You will
grant, I presume, that the needles are not parallel, but they both
point "north" w.r.t. their locations without contradiction.

Uncle Ben

Indeed. I'm sitting here at my office and every thing I see around
confirms me that I'm totally still. This is my "reality". But we all
know my chair, with my office, together with my whole city and the
continent is moving at around 1600 km/hour while, at the same time,
Earth is moving around the Sun at 30km/sec and the Solar System is
moving at 240km/sec towards...etc, etc.
So, what is the real "reality" or even does it makes sense to speak of
a "universal reality"?

Miguel Rios- Hide quoted text -

- Show quoted text -

Miguel, you are leaving out the essential factor:  relativity, i.e.,
these facts are relative to the frame of reference.  I say you
"really" are at rest w.r.t. your room.  And you "really" are in motion
w.r.t. a non-rotating heliocentric frame.

This is so simple.  An even simpler example: distance.  Can we say
that Chicago is really "farther"?  No, it depends on the reference
point.  "Fartherness" is not absolute. Chicago is farther than Buffalo
w.r.t. Albany. It is not farther w.r.t. Evanston. Both distances are
real, not illusory, but they are relative to a point of reference.

It seems not so clear when we turn to rates of clocks, because for all
of human history since clock have existed, we have thought of time as
absolute.  Now Einstein tells us that time is not absolute;  it, too,
is defined only w.r.t. a frame of reference.  This defies our common
sense, but SR tells us that it is just as real as distance being
defined relative to a point of reference.

Uncle Ben

I agree with you. My main argument is that for many here, the concepts
of "real", "perspective" and other relativity terms are difficult to
grasp.
It like, in other context, the financial problems. Is the vanishing of
trillion of dollars "real" or just an "illusion" due to market
values?. For many that question is also quite difficult to understand.
In the twin paradox, the traveling twin compares his clock (frame K')
with several clocks located along his path (frame K) and he measures
that his clock is running slow. In his "reality" his watch, he knows,
is running OK, so his logical conclusion is that, through these
measurements, he is experiencing time dilation. He is also observing
that he is moving,m by seeing all those clocks coming in and going out
from his location. If he would not have access to those clocks on the
path, he would not be able to detect any time dilation at all. While
the latter situation is not a different twin "reality", for the twin
himself his perceptions and senses would tell him nothing is
happening! He would not be able to say if he is moving or is still.

Miguel Rios- Hide quoted text -

- Show quoted text -

Miguel, you said:

In the twin paradox, the traveling twin compares his clock (frame K')
with several clocks located along his path (frame K) and he measures
that his clock is running slow. In his "reality" his watch, he knows,
is running OK, so his logical conclusion is that, through these
measurements, he is experiencing time dilation. He is also observing
that he is moving,m by seeing all those clocks coming in and going out
from his location. If he would not have access to those clocks on the

I think you would find that the "travelling" twin A (travelling w.r.t.
his brother B) would find that it is the clocks (B's) whizzing
backward (w.r.t. his [A's] ship) that are running slow. That is
because w.r.t. his own ship, he A is "really" not travelling, and they
[B's clocks] are. W.r.t. his brother's frame of reference, on the
other hand, his [A's] clocks are running slow. Both statements are
true and the effects are real.

It helps mightily when speaking of these things to specify the frame
of reference. You would not quote "the distance" to Chicago without
specifing the reference point. Similarly, you should not speak of a
clock's rate without specifying the frame of reference. The three
little letters "w.r.t." can correct most apparent contradictions in
SR.

Would you not agree that w.r.t. A's ship, A is not moving? (I don't
have to say "appears not to move", do I?

Uncle Ben
.

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